After malaria, human schistosomiasis is the parasitic disease with the highest morbidity and mortality worldwide. An estimated 236 million people are infected. Most are in sub-Saharan Africa. Complications lead to the deaths of 300,000 people each year. Pilot studies point to a high rate of underdiagnosis, whether in the sub-Saharan immigrant population residing in Spain or among individuals affected by outbreaks of autochthonous transmission (as happened in the 2003 case of four Spanish farmers who bathed in an artificial irrigation pool in Almería).
The “Consensus Document for the Management of Schistosomiasis in Primary Care” was recently published in the journal Atención Primaria [Primary Care]. Its aim is to establish clear recommendations so that primary care clinicians will be able to diagnose, manage, and treat this disease. The document was prepared by professionals who belong to the following five scientific societies: the Spanish Society of Family and Community Medicine, the Spanish Society of General Practitioners and Family Doctors, the Spanish Society of Primary Care Physicians, the Spanish Society for Pediatric Infectious Diseases, and the Spanish Society of Tropical Medicine and International Health (SEMTSI).
Agustín Benito Llanes, PhD, is the director of Spain’s National Center for Tropical Medicine (Carlos III Institute of Health) and the president of the SEMTSI. He told Univadis Spain, “The consensus document is invaluable for the management of cases imported by migrant populations coming from endemic areas and in the prevention of possible outbreaks in our country, especially urinary schistosomiasis.” He went on to explain, “This diagnostic strategy, which is also recommended by the European Centre for Disease Prevention and Control (ECDC), must be viewed in the context of the general management of patients with imported eosinophilia – eosinophilia being a condition that indicates that the individual may have a disease caused by a parasitic worm. I do know that primary care has been greatly affected and impacted by the pandemic, but new e-consultation and telemedicine models are making it possible for hospital specialists and primary care specialists to quickly get in touch with each other and work closely together. This technology can play a critical role in the shared care of patients with these types of diseases.”
The document recommends that serologic screening for schistosomiasis be considered for the following patients: asymptomatic individuals who have come from endemic regions and were exposed to freshwater sources; those who present with symptoms consistent with those of the disease; and patients for whom clinical exams or lab tests suggest acute schistosomiasis (eosinophilia is usually a sign). Screening for chronic schistosomiasis is indicated if the necessary resources for diagnosis and treatment are not available. The following considerations support screening asymptomatic individuals: the high prevalence of parasitic infection among migrants from endemic regions and among people who have traveled to those places; and the possibility of preventing serious complications and secondary transmissions.
The working group recommends that all at-risk individuals undergo screening, no matter how long it’s been since they were last in an endemic zone. This is because the parasites can live for over a decade. If primary care physicians don’t have access to diagnostic tests or to treatments, patients should be referred to specialists with experience in tropical diseases. A definitive diagnosis is made through the detection of blood fluke eggs in urine, stool, or body tissues. Through such detection, the species responsible for infection can be identified.